| 摘要 |
<p>1512693 Phosphate stripping of sewage UNION CARBIDE CORP 20 June 1975 [21 June 1974 4 June 1975] 26229/75 Heading C1C A mixed liquor of phosphate-containing sewage and activated sludge is aerated to reduce the BOD and cause the micro-organisms to take up phosphate. Phosphate-enriched sludge is separated to give a phosphate-free effluent. The enriched sludge is passed to a phosphate stripping zone to give supernatant liquor and settled sludge. At least part of the settled sludge is treated anaerobically to release phosphate, which is extracted by a lower phosphate-containing medium to transfer the soluble phosphate to this medium which is used to enrich the supernatant liquor. At least a portion of the anaerobic sludge is recycled to the aeration zone.</p> |
